Vacuum tube and mounting therefor



Nov. 30, 1948. i w. T. GIBSON I VACUUM TUBE AND MOUNTING THEREFOR Filed Jan. 5, 1946 2 Shets-Sheet 1 N WM) Nov. 30, 1948. w. T. GIBSON I 2,454,791

VACUUM TUBE AND MOUNTING THEREFOR Filed Jan. 5, 1946 n 2 $h6 $$h8et 2 Patented Nov. 30,1948

PATENT OFFICE 3 tha i vAcUUMmunnAN n MOUNTING THEREFOR Y W an Theme ..snh .t9.St. Q i- The pr inven ion relate to. e e on di cha e de c s. includin -v cu m o n n the ier.

tubes, and It is wen tnewnthat enedeeme'tt u e electrical circuits utilising elcctronjdischarge .de-.

Vices arise ire eeer contact etwee he pi or con s wh h serve-es erminels ert e ect d o e device. and th corr ondi sockets or onta t membe so eheld r- In Order to m ate es 'ncor; cont cte is...de-; sirable to solder theelectrode terminal oonduc: tors directly intg the associated circuit, While p c cs l t otta n' hiswcnd ha eb en made hit er o. he n eet e o so der n thermis- Hum e rect in t e c r ui ha nev be n. adopted b au e suc oposals ha e. not ee found practicable. It is the obi etef thi invn on t r ev a ea ly p a a method oice n c ine a e on discharge device into circuit utilising, only per.-. manent n t ns. t at i thout th use o contact devices. u

The ob ct s achieved c ord n t -t invenn by d g an. lec ron i char e devi e substantially e mpl e ven ese l n a condu t n ree and a n o der n ees. s cu edto t e lead-out conductors for the electrodes of the device.

The v t on also provides. an electrical c cuit arrangement comprising circuit elements including an electron discharge device having electrodes enclosed in a metallic screen andrigid lead-out conductors for the electrodes passing outside the screen, and wires een ecting the device to other circuitelements soldered to the said lead-out conductors.

It is possible to adapt st a t be acco i g to h a r or a ternatively w houtthe libasine arrangements.

The invention will be described with reference to the accompanying drawings in which Fig. 1 shows a sectional view of an electron discharge device according to the invention;

Fig. 2 shows a top view of the device;

Fig. 3 shows an exploded view of the details of the device;

Fig. 4 shows a transverse section through the cylindrical screen of the device;

Fig. 5 shows a perspective view of another device according to the invention; and

Figs. 6 and '7 show perspective views of r a soldering tag for the device of Fig. 5.

In the embodiment of the invention shown in Figs. 1 to 4, a vacuum tube l is enclosed in a close tion, ei W item, ondo E n an rd l elephones and Cables Limgland, a British company Application .fanua ry 5, 1946; Serial No. 639,286

.f In Great Britain January 16, 1945 fitti g metal'shield or can 2. The bottorn or the can is closed by a metal plate 3 carrying a metal boss. 4 which is designedto give mechanical pro: tection to the seal-off tip 5 of the vacuum tube envelope. The plate 3 has holes 6 adapted to clear the pinor rod terminals l for the electrodes of the vacuum tube. Over the plate 3 is placed a ring or disc 8 of insulating material such as phenol fibre. On top of this are placed connecting and sclderingtags 9 formed from bent metal strip, ,These tags are held in position by a star.-

shaped piece ll} of insulating material such as phenol fihre, and are intended to be soldered to the wires leading to the other elements of the circuitwith which the tube is used. This assembly, is locked into. position, for example, by spinhing over theend of the shielding can, as indicated in Fig. l. The inner ends of the soldering tags are securely connected, by welding or solder ing (-for example) tothe pin terminals'l. Means are provided for securing the can 2 into a chassis, whichmay be of metal. For example, close to the open end of the can several bosses H are res ed ou war s r und the i u e e o h can, The design should be such that the bosses are springy. The can 2 may then be inserted into a metal chassis plate I? which has ahole punched out to receive the can. This hole should be very slightly smaller in diameter than the cire cumscribi-ng circle oi the outsides of the bosses. The can may, therefore, be snapped through the hole theplatelz where it will be held inpositipnbut can be extracted by a steady pull when requ red- As shown in Fig. 1, the can 2 is formed so.;that it is locked into the chassis between the bosses ll resting on one side of the plate l2 and the-projecting rim l3 provided round the circumference of the can 2 which rests against the other side of the plate 12.

canmay also be provided with an additional elongated ridge or boss M (Fig. 3) arranged parallel to the axis of the vacuum tube, which can engage in an appropriate slot (not shown) in the hole in the plate l2, which will thus orientate the tube, thereby ensuring that the soldering tags 9 always come into the same position in relation to other equipment. This will facilitate the wiring of the tags 9 to the other equipment.

The boss 4 may be provided with an extension (not shown) which may be used as a finger grip 'to assist in inserting the vacuum tube into, and

6. Either a pressed glass valve base or a pinch stem may be used.

The arrangement which has just been described is also applicable without essential change to the type of vacuum tube in which thelead-out conductors for the electrodes are relatively flex, ible wires or the like. A somewhat simpler arrangement is, however, practicable only for the,

type in which these lead-out conductors are rigid pins or rods sealed through the envelope of the tube. This embodiment is shown in Figs. 5, 6 and 7. The can 2 is in this case closed by the plate 3 carrying the boss 4 as in Figs. 1 to 4. The tags}! and insulating discs 8 and H) are however omitted, the can 2 being simply spun over the plate 3.

To each of the pin terminals of the tube is attached a tag l5 shown enlarged in Fig. 7. This tag is made from a fiat L-shaped metal detail of the shape shown in Fig. 6, the end portion I6 being rolled over in the manner shown in Fig. 7 to form a socket which is slipped over the projecting end of the pin terminal of the vacuum tube, and is then securely welded or soldered thereto. A hole i! at the other end of the tag may be used for anchoring the wire to which the tag. is subsequently soldered when the tube is to An alternative way of carrying out the inven-' tion is applicable in the case of the well known type of tube already provided with a practically totally enclosing metal screen, and having pin terminals projecting beyond the closing metal base plate. A holder of the kind usually used with such a tube is obtained, and the tube is inserted therein in the usual manner. Each of the pins is then soldered or welded into the corresponding socket of the holder, and the complete assembly so formed is treated as a unit and is then fixed in the chassis in any convenient way, for example by using the normal fixing means for the holder. The Wires leading from the other circuit.

elements are then soldered to the holder tags in the usual way.

The case where the pin terminals of the vac- 4 uum tube make contact with flat springs in the holder may be treated in a similar way, the pins being soldered or welded to the fiat springs.

What is claimed is:

1. An electron discharge device comprising an envelope of insulating material having conductors for the electrodes of the device sealed through said envelope, a metal envelope enclosing said insulating envelope, a base plate provided with apertures and mounted on said metal envelope with said conductors passing through said apertures, and metallic tags secured to said conductors adjacent said apertures whereby said discharge deviceis efl'ectively screened.

2. An'electron discharge device according to claim'l in which said tags are shaped to bend from the point at which they are secured to said conductors. .towards said apertures and which further comprises insulating plates securing said tags adjacent said apertures.

3. An electron discharge device according to claim 1 further'c'omprising bosses raised on the outside surface of the said metal envelope for removably locking the device into a corresponding aperture in a holder. I I

4 ..An electron discharge device comprisin an envelope of insulating material having a vacuum tight seal-ofi tip and conductors for the electrodes of the device sealed through said envelope, a metal envelope enclosing said insulating envelope, a base plate provided with apertures and a boss an'dmounted on said metal envelope with said conductors passing through said apertures and said boss fitting around said seal-off tip, and metallic tags secured'to said conductors adjacent saida'p'e'rture's, whereby said discharge device is effectively screened.

5. An electron discharge device according to claim 1. further comprising means for insulatedly securing said tags to said base plate.

6. An electron discharge device according to claim 1 in which one end of each said tag is secured to its respective conductor and the other endcomprises means for rigidly connecting the tube to an external circuit and which further comprises means for insulatedly securing parts of the tags intermediate the ends thereof to the base plate.

' WILLIAM THOMAS GIBSON.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number 

